With development of mobile communications technologies, intelligent terminals are increasingly popular, and services that a terminal can process are increasingly abundant. However, power consumption of the terminal also continuously increases. To improve power saving performance of the terminal, a discontinuous reception (DRX) technology is introduced.
A data stream of packets generally occurs in a burst mode. There is data transmission in a period of time, but no data transmission in a next period of time. The DRX technology is based on this. A DRX cycle is configured, and as shown in FIG. 1, the DRX cycle includes two periods of time: an active period (also referred to as on duration (OD)) and a sleep period (also referred to as opportunity for DRX).
A terminal and a RAN device may maintain a same DRX cycle. The terminal listens to a physical downlink control channel (PDCCH) in an active period, and receives various types of scheduling and other control information carried on the PDCCH, and the terminal does not listen to the PDCCH in a sleep period to reduce power consumption.
Because the terminal does not listen to the PDCCH in the sleep period, a radio access device does not perform scheduling grant in the sleep period, and performs scheduling grant in a next active period. Therefore, a delay of data transmission is increased. In particular, for a service such as a voice service that is delay sensitive, this delay affects user experience.